Noise in thin-film YBa2Cu3O7step-edge junction RF SQUIDS
- 1 May 1994
- journal article
- Published by IOP Publishing in Superconductor Science and Technology
- Vol. 7 (5) , 260-264
- https://doi.org/10.1088/0953-2048/7/5/008
Abstract
We describe the noise performance of thin-film YBa2Cu3O7 RF SQUIDS fabricated on MgO substrates with single step-edge Josephson junctions. A substantial range of noise levels has been observed for devices having similar electrical parameters (inductance, critical current, RF frequency). The best devices have white-noise levels below 10-4 phi 0 Hz-1/2 when operated at a frequency of 170-200 MHz and have 1/f noise corners of a few hertz. Measurements of the VRF versus LRF characteristics of one SQUID, indicate that intrinsic device noise dominates the measured total noise of these devices. The white noise of all devices exceeds the predictions of the theory of Kurkijarvi at al. by a large factor, apparently because of non-ideal behaviour of step-edge Josephson junctions.Keywords
This publication has 17 references indexed in Scilit:
- In-situ growth of epitaxial YBa2Cu3O7 thin films by on-axis unbalanced d.c. magnetron sputteringThin Solid Films, 1993
- Sensitive RF-SQUIDs and magnetometers operating at 77 KIEEE Transactions on Applied Superconductivity, 1993
- Progress in RF-SQUIDsIEEE Transactions on Applied Superconductivity, 1993
- New techniques for fabricating step-edge junctions for high-T/sub c/ SQUIDs on MgO substratesIEEE Transactions on Applied Superconductivity, 1993
- In situ growth of epitaxial YBa2Cu3O7 thin films by on-axis unbalanced direct current magnetron sputteringApplied Physics Letters, 1993
- YBa2Cu3O7 thin-film step junctions on MgO substratesApplied Physics Letters, 1992
- Low-noise YBa2Cu3O7 rf SQUID magnetometerApplied Physics Letters, 1992
- Substrate step-edge YBa2Cu3O7 rf SQUIDsApplied Physics Letters, 1991
- Properties of RF-SQUIDs fabricated from epitaxial YBa2Cu3O7filmsSuperconductor Science and Technology, 1991
- Investigation of RF SQUIDs made from epitaxial YBCO filmsSuperconductor Science and Technology, 1990